Electrochemical properties of LiNiO2 and LiNiO2 substituted with Ga, Al and/or Ti

The LiNi1−yMyO2 specimens with compositions LiNiO2, LiNi0.975Ga0.025O2, LiNi0.975Al0.025O2, LiNi0.995Ti0.005O2, and LiNi0.990Al0.005Ti0.005O2 were synthesized by wet milling and solid-state reaction method. All the synthesized samples possessed the α-NaFeO2 structure of the rhombohedral system (space group; R 3 ¯ m ) with no evidence of any impurities. Among all the specimens, LiNi0.990Al0.005Ti0.005O2 has the largest first discharge capacity, 196.3 mAh/g, at a rate of 0.1 C. At n = 50 LiNiO2 has the largest discharge capacity, 126.7 mAh/g. LiNiO2 has the best cycling performance, its degradation rate of discharge capacity being 0.73 mAh/g/cycle.